[To those who have yet to see The Girl With the Dragon Tattoo: Beware, here thar be spoilers.]

Plenty of cinema’s violent scenes have been underscored by equally violent music (take the staccato stabs of Bernard Herrmann’s Psycho theme), but sometimes the best way to bring the horror into full relief is with somethingcompletelyincongruous. One of the few times The Girl With the Dragon Tattoo takes a break from Trent Reznor’s thrumming, entrancing score is during one of its more harrowing scenes, when Martin Vanger (Stellan Skarsgard) has trapped Mikael Blomkvist (Daniel Craig) in his murder den and is preparing to wreak havoc on his pursuer. What music does the serial killer and modern-furniture enthusiast choose to set the mood? The 1988 new age-y hit “Orinoco Flow” by Enya, previously played mostly in less dangerous environs like elevators or waiting rooms.

“I have to give credit where credit is due,” Fincher tells EW. “We knew we needed a moment of levity. I said, ‘He should walk over and turn on music, because he doesn’t like to kill, he doesn’t like to hear the screams, without hearing his favorite music.’ And Daniel Craig hopped up and picked up his iPod and scrolled through it and said, ‘Here it is.’ And we all almost pissed ourselves, we were laughing so hard. No, actually, it’s worse than that. He said, ‘Orinoco Flow!’ Everybody looked at each other, like, what is he talking about? And he said, ‘You know, “Sail away, sail away…”’ And I thought, this guy is going to make Blomkvist as metro as we need.”

Don’t get him wrong, even if you’ve always suspected that there was something evil lurking just below the surface of the adult-contemporary genre, David Fincher insists it has nothing to do with the song itself. “It’s just that [Vanger] likes soothing music as he does his deeds.” Fincher adds. “It wasn’t a reflection on the track – it’s not like it’s part of the serial-killer playlist on iTunes.”